New perspectives for the Barkhausen effect

The precise connections between the Barkhausen effect and non-equilibrium critical phenomena and self-organized criticality (SOC) have been strongly debated in the past few years. We review the recent theoretical studies of the Barkhausen effect and discuss their relevance to quantitatively understand the experiments. We compare the results of disordered spin models, micromagnetic equations, and models for rigid and flexible domain walls with experiments on amorphous and polycrystalline ferromagnetic alloys. In particular, we discuss the theoretical predictions for the critical exponents of the power law decay and for the cutoff of the avalanche distributions. We conclude that models based on the dynamics of a flexible domain wall are the most successful in explaining existing experimental data.